I am writing to see if there is any possibility of having the demerit points dropped from my ticket.

I was driving Eastbound on Hwy 402 just outside Sarnia in an area that is well-known for high winds and terrible winter weather. On days that the sun is shining only minutes away in Sarnia or London, this area can be blizzard-like. There are two lanes heading eastbound and two heading westbound, divided by a ditch on either side of a natural median that is approximately 100' wide.

I was driving a full-size Ford service van that is top-heavy and very difficult to control in high winds, especially when loaded with tools and material. I was doing approximately the speed limit of 100 km/hr in the fast lane after passing a slower driver. It had rained there for the last two days and at the time the weather was cloudy, drizzly and dismal. The roads were wet.

Basically, a very strong gust of wind hit my vehicle broadside from the driver's side. Naturally, I feared that I was being pushed into the lane beside me, so my instinctive reaction was to pull the steering wheel to the left to try and remain in my lane. Unfortunately, just as I did so the gust subsided and I over-compensated, hitting the soft shoulder. Like I said, it had rained there for the two days previous and the shoulder was very soggy and soft. I ended up ditching my vehicle after an unsuccessful attempt to get back on the road, and came to a stop in the middle of the grassy median.

I am 41 years old and have an excellent driving record, haven't even had a speeding ticket in many, many years. I think the only one I ever got was doing 60 km/hr in a 50 km/hr zone.

Originally the OPP officer was going to charge me with Careless Driving, but changed her mind. Instead, she charged me with "Fail to drive in marked lane".

Do I have any chance of fighting this? I dont even mind the fine of $110 because let's face it, I was the one behind the wheel and I was the one who drove into the ditch... there's no arguing that, so I don't mind paying the fine... it's the points I am worried about.

Also, if I were to appeal it or go to court or whatever, is there any chance that I could somehow end up being charged with Careless afterall?

Out of curiosity, why would you be worried about the points if your record is reasonably clean? Here are a few facts that you should know:
1) Insurance companies don't look at points, only at convictions and whether they are major or minor. Generally you can treat EVERYTHING as a "minor" conviction (speeding 1km/h over the limit, speeding 40km/h over the limit, running a red, not wearing a seat belt). Generally only real major stuff, such as Careless Driving, Stunting (better known as "street racing") or not stopping for a school bus is treated as "major." Just a small caveat: some companies will treat speeding by as little as 45km/h over the limit as "major" even though it doesn't fall into the "stunting" range (50+).
2) Demerit points disappear 2 years after your conviction date.
3) Unless you rack up 9+ demerit points (which would bring you to an interview where they decide whether they suspend your license), which won't happen to most drivers over a period of 2 years, you have nothing to worry about.

I'm a habitual speeder here in Ontario (not so much in jurisdictions with more reasonable speed limits), and I get pulled over on an average of once a year. I never had more than 3 demerits on my record. If I got convicted of everything I ever got charged with, the most I would have had on my record at any point in time would have been 6 (which is still below the limit of 9).
If you almost never get pulled over, it might even be easier for you to just pay up and forget about it. Most insurance companies won't ding you a lot for a single conviction (I think only State Farm gets anal on that count), but most others will either forgive the first conviction or give you a minimal increase (5-10%).

What kind of a man would put a known criminal in charge of a major branch of government? Apart from, say, the average voter.